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1.
J Dairy Sci ; 104(9): 9931-9947, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34176632

RESUMO

Understanding the regulation of cellular AA uptake as protein supply changes is critical for predicting milk component yields because intracellular supplies partly regulate protein synthesis. Our objective was to evaluate cellular uptake and kinetic behavior of individual AA when cells are presented with varying extracellular AA supplies. Bovine primary mammary epithelial cells were grown to confluency and transferred to medium with an AA profile and concentration similar to that of plasma from dairy cows for 24 h. Treatments were 4 AA concentrations, 0.36, 2.30, 4.28, and 6.24 mM, which represented 16, 100, 186, and 271% of typical plasma AA concentrations, respectively, in lactating dairy cows. Twenty-four plates of cells (89.4 × 19.2 mm) were assigned to each treatment. Cells were first subjected to treatment medium enriched with 15N-labeled AA for 24 h and then incubated with treatment medium enriched with 13C-labeled AA for 0, 15, 60, 300, 900, 1,800, and 3,600 s. Intracellular free AA, intracellular protein-bound AA, and extracellular medium free AA were analyzed for concentrations and isotopic enrichment using gas chromatography-mass spectrometry. A dynamic, 12-pool model was fitted to the data for 14 AA to derive unidirectional uptake and efflux, protein turnover, transamination, oxidation, and synthesis. The derived concentration for half the maximal uptake (km) indicated no saturation of AA uptake at typical in vivo concentrations for 11 of the 14 AA. Arginine, Pro, and Val appeared to exhibit saturation kinetics. Net uptake of all essential AA except Phe was positive across treatments. Most nonessential AA exhibited negative net uptake values. Efflux of AA was quite high, with several AA exhibiting greater than 100% efflux of the respective influx. Intracellular pool turnover was rapid for most AA (e.g., 2 min for Arg), demonstrating plasticity in matching needs for protein translation to supplies. Intracellular AA concentrations increased linearly in response to treatment for most AA, whereas 9 AA exhibited quadratic responses. Amino acid uptake is responsive to varying extracellular supplies to maintain homeostasis. No saturation of uptake was evident for most AA, indicating that transporter capacity is likely not a limitation for most AA except possibly Arg, Val, and Pro in mammary epithelial cells.


Assuntos
Aminoácidos , Lactação , Animais , Bovinos , Células Epiteliais , Feminino , Glândulas Mamárias Animais , Leite , Proteínas do Leite
2.
J Dairy Sci ; 103(10): 8948-8966, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32861491

RESUMO

Understanding uptake of AA by mammary tissue as supply varies is critical for predicting milk component production. Our objective was to develop an in vitro method to quantify cellular uptake, efflux, and intracellular metabolism of individual AA that could be implemented for evaluating these factors when AA supply and profile are varied. Bovine primary mammary epithelial cells were grown to confluency and exposed to medium with an AA profile and concentration similar to lactating dairy cow plasma for 24 h. Cells were then preloaded in medium enriched with 15N-labeled AA for 24 h followed by removal of the 15N-labeled medium and incubation with medium enriched with 13C-labeled AA for 0, 15, 60, 300, 900, 1,800, and 3,600 s. Extracellular free AA and intracellular free and protein-bound AA were analyzed for concentrations and isotopic enrichment by gas chromatography-mass spectrometry. A dynamic, 12-pool model was constructed representing extracellular and intracellular free and protein-bound pools of an AA, and their respective 15N and 13C isotopes. Markov chain Monte Carlo simulation (n = 5,000) was conducted to evaluate prediction errors by deriving standard errors and posterior distributions for rate constants, fluxes, and pools. Cellular Ala influx and efflux were higher than Leu, reflecting Ala role in driving system L transport and the high capacity of sodium-dependent transport. The Ala and Leu turnover rates were 181 and 95, 580 and 857, and 74 and 157% per hour for extracellular, intracellular, and fast protein-bound pools, respectively. The intracellular and extracellular Ala to Leu ratios were quite different, meaning the blood AA profile is not the AA profile provided for protein translation. The high level of exchange and rapid turnover of pools provide a mechanism for matching the AA supplies to the precision necessary for translation. This also understates the importance of using experimental medium similar to what is observed in vivo given that some AA depend on other AA for influx (exchange driven). The average root mean squared prediction error across the isotope enrichments, pools, and concentrations was 9.7 and 14.1% for Ala and Leu, respectively, and collinearity among parameters was low, indicating adequate fit and identifiability. The described model provides insight on individual AA transport kinetics and a method for future evaluation of AA transport and intracellular metabolism when subjected to varying AA supplies.


Assuntos
Aminoácidos/metabolismo , Bovinos , Células Epiteliais/metabolismo , Glândulas Mamárias Animais/citologia , Alanina/metabolismo , Aminoácidos/sangue , Animais , Transporte Biológico , Feminino , Técnicas In Vitro/veterinária , Marcação por Isótopo/veterinária , Cinética , Lactação , Leucina/metabolismo , Glândulas Mamárias Animais/metabolismo , Proteínas do Leite/metabolismo
3.
J Dairy Sci ; 102(10): 8977-8985, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31421874

RESUMO

Extracellular amino acid profiles affect intracellular AA concentrations and profile as well as signaling proteins that regulate protein translation rates. The objective of this study was to assess whether various extracellular AA profiles and varied ratios of Lys to Met would increase the phosphorylation of signaling proteins related to protein metabolism. Six AA profiles, reflecting Dulbecco's modified Eagle's medium (DMEM), blood meal (BM), corn gluten meal (CGM), casein (CAS), plasma of lactating cows (PLA), and a negative control (NEG) represented the first factor (F1), and the ratio of Lys to Met (unaltered or set to 3:1) was the second factor (F2). Treatments were arranged in a 6 × 2 factorial manner, resulting in 12 treatments that were replicated 4 times. The total AA masses for all treatments were set to 659 mg/L (63% of DMEM) except NEG (0 mg/L). Confluent mammary epithelial cells were exposed to treatment media for 80 min (SD = 7.4). Intracellular concentrations of 17 AA were changed according to F1. The Met and Leu percent of total intracellular AA mass, as an example, varied from 0.58 (PLA) to 6.94 (NEG, +F2) for Met and 0.05 (NEG, -F2) to 4.63 (CGM, +F2) for Leu. Overall, balancing for Lys and Met at a 3:1 ratio increased intracellular concentrations of Lys and Met by 54 and 71%, respectively. Within the mechanistic target of rapamycin (mTOR) pathway, phosphorylation of mTOR (Ser2448), ribosomal protein S6 (Ser235/236), and eukaryotic initiation factor 4E binding protein 1 (Thr37/46) (4EBP1) were increased by all 5 AA profiles compared with the NEG control. We found no differences in phosphorylation state among the 5 AA profiles, indicating lack of sensitivity to various AA profiles. This lack of sensitivity between AA profiles might also be due to assay imprecision or other experimental limitations. Only phosphorylation of 4EBP1 was increased for F2. Phosphorylation of eukaryotic initiation factor 2 α subunit (Ser51) was unaffected by either F1 or F2 factors. Regression analyses indicated that intracellular concentrations of Met, Thr, Ile, and Leu predicted phosphorylation of mTOR-related proteins with adequate precision and accuracy, suggesting that multiple EAA dictate regulation, regardless of AA ratios. Changes in extracellular AA profiles translated to modified intracellular AA profiles, and no single profile uniquely stimulated phosphorylation of the mTOR pathway-related proteins.


Assuntos
Aminoácidos/metabolismo , Bovinos/fisiologia , Biossíntese de Proteínas , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Animais , Caseínas/metabolismo , Células Epiteliais/metabolismo , Fator de Iniciação 4E em Eucariotos/metabolismo , Espaço Extracelular/metabolismo , Feminino , Lactação , Lisina/metabolismo , Glândulas Mamárias Animais/metabolismo , Metionina/metabolismo , Fosforilação , Proteína S6 Ribossômica/metabolismo
4.
Phys Chem Chem Phys ; 20(17): 11549-11553, 2018 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-29651478

RESUMO

Astatine-211 is considered to be one of the most promising alpha-emitters in targeted alpha therapy (TAT). However, its development has been hindered by its not so well understood chemistry. Hence, any attempt to understanding it better is imperative. Here, we show through DFT calculations that the neutral endohedral Al13 cluster follows a reactivity pattern very similar to At, more than any other halogen. The halogen and alkali bonding with Al13 and At presented a strong similarity in their charge transfer processes. Moreover, upon the interchange of At with Al13, we found a stable configuration of the compound corresponding to the astatination of aryliodonium salts, which have been considered as possible precursors for the synthesis of 211At-labeled tracers. Our results provide promising proof of concept that the Al13 cluster mimics the behaviour of At and might help in better understanding its chemistry and in streamlining the chemical processes of radiolabeling biomolecules.


Assuntos
Astato/química , Halogênios/química , Radioquímica , Partículas alfa
5.
J Dairy Sci ; 99(12): 9703-9715, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27720148

RESUMO

The objective of this work was to assess the effects of age and gastrointestinal location (rumen vs. colon) on bacterial community diversity and composition, as well as short-chain fatty acid profiles of preruminant male Holstein calves on an intensive milk replacer feeding program. Thirty-two calves were fed at 2% of their body weight (dry matter basis) from d 10 until harvest. Sixteen calves were euthanized at 2wk and another 16 at 4wk of age to collect digesta samples from the rumen and colon. The rumen and colon bacterial communities of preruminant calves showed a similar degree of diversity (i.e., Shannon index) whereas composition differed considerably. The colonic bacterial population was characterized by dominance of lactic acid bacteria such as Lactobacillus, Streptococcus, Enterococcus, and Bifidobacterium. In addition, colonic short-chain fatty acid and lactic acid concentrations were between 50 and 850% higher than in the rumen, indicating greater fermentative activity in the colon. On the other hand, in the rumen, no genus over-dominated and more variation was present among calves. Because of an active reticular groove and low starter grain intake during the first 1 to 3wk of life, ruminal fermentation may not contribute to significant metabolizable energy supply until after 4wk of life in intensively fed calves. Until then, calf hindgut fermentation, characterized by high abundance of lactic acid bacteria along with increased lactate and butyrate concentrations, could be beneficial for intestinal health and survival of the calf during the first weeks of life.


Assuntos
Ração Animal , Microbioma Gastrointestinal , Rúmen , Animais , Bovinos , Dieta/veterinária , Ácidos Graxos Voláteis , Leite
6.
J Dairy Sci ; 99(8): 6324-6333, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27179863

RESUMO

The objectives of this study were to compare 2 milk replacers containing only milk proteins with or without supplemental Met, and to compare a milk replacer containing hydrolyzed wheat protein at 4.5% of dry matter (DM) and supplemental Lys and Met against the 2 all-milk-protein formulas, by assessing their effect on the growth performance, efficiency, and plasma urea nitrogen of pre-weaning Holstein calves. Thus, 57 Holstein calves were allotted to the following 3 treatments: (1) a skim milk plus whey protein concentrate-based milk replacer (SMWP) containing about 2.6% Lys and 0.6% Met on a DM basis; (2) SMWP + M based on skim milk and whey proteins, containing about 2.6% Lys, and supplemental Met to reach 0.9% on a DM basis; and (3) a skim milk plus whey protein concentrate plus 4.5% of the DM as hydrolyzed wheat protein based milk replacer (HWP + LM) where the wheat protein replaced 50% of the whey protein concentrate, and also contained supplemental Lys and Met to match the profile of SMWP + M (i.e., Lys 2.6 and Met 0.9% on DM basis). No difference in any of the responses was observed by supplementing the milk protein based formula with Met or when hydrolyzed wheat protein was added to the formula. Results indicate that (1) a milk replacer based on skim milk protein and whey protein with a Lys concentration of ~2.6% does not benefit from Met supplementation, and (2) milk replacer containing 4.5% of the DM as hydrolyzed wheat protein and supplemented with Lys and Met can support the same growth performance as milk protein-based formulas.


Assuntos
Metionina , Proteínas do Leite , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos , Leite , Triticum
7.
J Dairy Sci ; 99(7): 5793-5807, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27179875

RESUMO

Glucagon-like peptide 2 (GLP-2) is a peptide released by the lower gut that has potent trophic and restorative effects on the intestinal epithelium. Two experiments were conducted to assess the effects of feeding rate and either metabolizable or nonmetabolizable glucose supplementation on GLP-2 concentrations in plasma and intestinal development in Holstein calves. In the first experiment, 48 newborn calves were assigned to 12 treatments (n=4) corresponding to the factorial combination of 4 milk feeding amounts [1.75, 1.32, 0.88, and 0.44% of body weight (BW) as dry matter (DM)] and 3 oral supplementation treatments (nonsupplemented, glucose-supplemented, and 3-O-methyl glucose-supplemented). In the second experiment 30 newborn calves (n=10) were fed milk at a fixed rate of 1.75% of BW as DM and assigned to the same glucose supplementation treatments used in experiment 1 to investigate effects on intestinal development. In the first experiment, we found a saturating response of plasma GLP-2 to increasing feeding levels. The feeding rate at which 50% of the maximal GLP-2 release occurred was estimated to be 0.53% of BW as DM or 30.3% of the maximum feeding rate (1.75% of BW as DM), whereas maximal secretion was estimated to be about 98.6 pmol/L. In turn, feeding 75, 50, or 25% of the maximal feeding rate (i.e., 1.75% BW as DM) resulted in plasma GLP-2 concentrations 87, 72, and 49% of that in fully fed calves, respectively. Neither metabolizable nor nonmetabolizable glucose supplementation affected GLP-2 secretion and no interaction with feed intake level was detected. In the second experiment, no effect of glucose supplementation was observed on intestinal growth, mucosal cell proliferation, or expression of genes related to the actions of GLP-2. Nonetheless, we observed that a pool of genes of the GLP-2 signaling pathway was more abundantly and coordinately regulated in the colon than in the ileum of these animals, indicating an opportunity for dietary induction of the peptide in this organ. In conclusion, during this experiment, plasma GLP-2 concentrations responded in a diminishing return fashion to milk intake but not to glucose supplementation, even at milk consumption levels of only 0.4% of BW as DM.


Assuntos
Dieta/veterinária , Peptídeo 2 Semelhante ao Glucagon/metabolismo , Leite , Ração Animal , Animais , Bovinos , Glucose
8.
J Dairy Sci ; 99(8): 6714-6736, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27236753

RESUMO

To improve dietary protein use efficiency in lactating cows, mammary protein synthesis responses to AA, energy substrates, and hormones must be better understood. These entities exert their effects through stimulation of mRNA translation via control of initiation and elongation rates at the cellular level. A central protein kinase of this phenomenon is the mammalian target of rapamycin (mTOR), which transfers the nutritional and hormonal stimuli onto a series of proteins downstream through a cascade of phosphorylation reactions that ultimately affect protein synthesis. The objective of this work was to further develop an existing mechanistic model of mTOR phosphorylation responses to insulin and total essential AA to include the effects of specific essential AA and acetate mediated by signaling proteins including protein kinase B (Akt), adenosine monophosphate activated protein kinase (AMPK), and mTOR and to add a representation of milk protein synthesis. Data from 6 experiments in MAC-T cells and mammary tissue slices previously conducted in our laboratory were assembled and used to parameterize the dynamic system of differential equations representing Akt, AMPK, and mTOR in their phosphorylated and dephosphorylated states and the resulting regulation of milk protein synthesis. The model predicted phosphorylated Akt, mTOR, AMPK, and casein synthesis rates with root mean square prediction errors of 16.8, 28.4, 33.0, and 54.9%, respectively. All other dependent variables were free of mean and slope bias, indicating an adequate representation of the data. Whereas mTOR was not very sensitive to changes in insulin or acetate levels, it was highly sensitive to leucine and isoleucine, and this signal appeared to be effectively transduced to casein synthesis. Although prior work had observed a relationship with additional essential AA, and data supporting those conclusions were present in the data set, we were unable to derive significant relationships with any essential AA other than leucine and isoleucine. The signaling properties and dynamics of AMPK under nutrient depletion and sufficiency, the responses to additional essential AA, and the consequent effects on protein synthesis remain to be better understood.


Assuntos
Aminoácidos/metabolismo , Caseínas/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Acetatos/metabolismo , Animais , Bovinos , Feminino , Insulina/metabolismo , Lactação , Glândulas Mamárias Animais/metabolismo , Fosforilação , Transdução de Sinais/efeitos dos fármacos , Sirolimo/farmacologia
9.
J Dairy Sci ; 99(12): 9682-9702, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27720150

RESUMO

Digestive disorders are common during the first few weeks of life of newborn calves. Prebiotics are nondigestible but fermentable oligosaccharides that modulate growth and activity of beneficial microbial populations, which can result in enhanced gut health and function. Galactooligosaccharides (GOS) have demonstrated such prebiotic potential. In this study, the effect of GOS supplementation on intestinal bacterial community composition and fermentation profiles; intestinal health, development, and function; and growth was evaluated in dairy calves fed for high rates of growth. Eighty male Holstein calves were assigned either to a control treatment consisting of commercial milk replacer or to a GOS-rich (i.e., 3.4% of dry matter) milk replacer treatment. After 2 and 4wk, 8 calves per treatment were slaughtered at each age. Samples of intestinal digesta and tissue were collected for assessment of bacterial communities, short-chain fatty acid concentrations, in vitro measurement of nutrient transport and permeability, histomorphology, and gastrointestinal organ size. The remaining 48 calves continued to wk 8 to measure body growth, nutrient intake, and fecal and respiratory scores. Calves fed GOS displayed greater Lactobacillus and Bifidobacterium relative abundance and more developed intestinal epithelial structures, but also had greater fecal scores presumably related to greater colonic water secretion. Control calves showed slightly better growth and milk dry matter intake. Size of intestinal organs, intestinal nutrient transport, and epithelium paracellular resistance were not affected by treatment. Excessive GOS supplementation had both prebiotic and laxative effects, which led to slightly lower growth performance while promoting commensal bacteria population and greater intestinal epithelium growth.


Assuntos
Suplementos Nutricionais , Microbioma Gastrointestinal , Prebióticos , Ração Animal , Animais , Bovinos , Dieta/veterinária , Ácidos Graxos Voláteis , Fezes/química , Substitutos do Leite/química
10.
Phys Chem Chem Phys ; 17(12): 7624-8, 2015 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-25715330

RESUMO

Silicene, the graphene-like crystal formed by the Si hexagonal lattice, presents a periodic buckled structure whose origin is due to the pseudo Jahn-Teller instability on each of its planar six membered rings. This has been attributed to the coupling of the planar D6h ground state with the first b2g excited state through a b2g vibrational mode. Here we show, by explicitly calculating the vibronic coupling constants through a complete study of the PJT effect, that the vibronic coupling of the ground state with only one excited state to explain the planar instability is inconsistent with the linear multilevel PJT effect theory. It is also shown that in order to have consistency, the PJT model should include the next excited state, which is symmetry compatible coupled to the puckering mode. This is done by the analysis, based on DFT and TDDFT calculations, of the vibronic instability of the ground state of hexasilabenzene, the basic silicon hydrogenated hexagonal ring unit defining silicene.

11.
Int J Clin Pract ; 67(10): 947-56, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23961850

RESUMO

AIM: Real-life studies are needed to confirm the clinical relevance of findings from randomised controlled trials (RCTs). This study aimed to assess the effectiveness and tolerability of vildagliptin add-on vs. other oral antihyperglycaemic drugs (OADs) added to OAD monotherapy in a real-life setting, and to explore the advantages and limitations of large-scale 'pragmatic' trials. METHODS: EDGE was a prospective, 1-year, worldwide, real-life observational study in which 2957 physicians reported on the effects of second-line OADs in 45,868 patients with T2DM not reaching glycaemic targets with monotherapy. Physicians could add any OAD, and patients entered either vildagliptin or (pooled) comparator cohort. The primary effectiveness and tolerability end-point (PEP) evaluated proportions of patients decreasing HbA(1c) > 0.3%, without hypoglycaemia, weight gain, peripheral oedema or gastrointestinal side effects. The most clinically relevant secondary end-point (SEP 3) was attainment of end-point HbA(1c) < 7% without hypoglycaemia or ≥ 3% increase in body weight. RESULTS: In this large group of T2DM patients, a second OAD was added at mean HbA(1c) of 8.2 ± 1.3%, with no baseline HbA(1c) difference between cohorts. Second-line OAD therapy attained the PEP in the majority of patients, with higher attainment in those prescribed a vildagliptin-based regimen. The adjusted odds ratio was 1.49 (95% CI: 1.42, 1.55; p < 0.001). In patients with baseline HbA(1c) ≥ 7%, SEP 3 was achieved by 35% of patients on a vildagliptin-based combination and by 23% of those receiving comparator combinations. The adjusted odds ratio was 1.96 (95% CI: 1.85, 2.07; p < 0.001). Safety events were reported infrequently and safety profiles of vildagliptin and other OADs were consistent with previous data. CONCLUSION: EDGE demonstrates that in a 'real-life' setting, vildagliptin as second OAD can lower HbA(1c) to target without well-recognised OAD side effects, more frequently than comparator OADs. In addition, EDGE illustrates that conducting large-scale, prospective, real-life studies poses challenges but yields valuable clinical information complementary to RCTs.


Assuntos
Adamantano/análogos & derivados , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Nitrilas/administração & dosagem , Pirrolidinas/administração & dosagem , Adamantano/administração & dosagem , Adamantano/efeitos adversos , Administração Oral , Diabetes Mellitus Tipo 2/sangue , Quimioterapia Combinada , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/induzido quimicamente , Hipoglicemiantes/efeitos adversos , Masculino , Pessoa de Meia-Idade , Nitrilas/efeitos adversos , Estudos Prospectivos , Pirrolidinas/efeitos adversos , Vildagliptina
13.
J Dairy Sci ; 93(5): 2143-52, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20412929

RESUMO

Forty Holstein cows were used in an 8-wk randomized trial to evaluate the effects of feeding combinations of forages with improved fiber digestibility on performance during early lactation. Treatments were arranged as a 2 x 2 factorial to include silage from normal (NCS) or brown midrib (BMR) corn silage with or without 10% Tifton 85 bermudagrass hay (T85). In a simultaneous digestion trial, degradation and passage kinetics and ruminal fermentation parameters were evaluated in a 4 x 4 Latin square design trial using late-lactation Holstein cows fitted with ruminal cannulas. Dry matter intake (DMI) and neutral detergent fiber (NDF) intake were greater with BMR than with NCS; however, milk yield and composition were similar among corn silage types. Inclusion of T85 reduced milk yield but supported higher milk fat percentage, resulting in similar yields of energy-corrected milk. Blood glucose concentrations were higher for BMR compared with NCS, and inclusion of T85 increased blood urea N concentrations. Treatments did not alter liquid or solid phase passage rates or rumen turnover. Corn silage type did not affect ruminal pH or volatile fatty acid concentrations, but inclusion of T85 increased pH and molar proportion of acetate but decreased butyrate. Molar proportions of propionate were greater for NCS and T85 compared with BMR and T85, resulting in an interaction. Results of this trial indicate that combinations of forages with improved fiber digestibility can be used to support intake and performance of cows during early lactation.


Assuntos
Bovinos/fisiologia , Cynodon/metabolismo , Dieta/veterinária , Fibras na Dieta/metabolismo , Lactação/fisiologia , Silagem , Zea mays/metabolismo , Animais , Bovinos/metabolismo , Feminino , Distribuição Aleatória
14.
J Dairy Sci ; 93(11): 5280-5, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20965344

RESUMO

Forty-four lactating Holstein cows (173±30 DIM, 42.5±6.8 kg of milk, 4.03±0.69% fat, 674±78 kg of body weight) were used in an 8-wk, completely randomized trial with a 2 × 2 factorial arrangement of treatments to determine the effect of forage source and supplemental cellulase enzyme on performance. Treatments included 2 forage combinations (corn silage plus 12.2% dry matter, DM, from either alfalfa hay or Tifton 85 bermudagrass haylage) with or without a commercial cellulase enzyme applied to the total mixed ration at the rate of 4 g/head per day (Promote N.E.T.-L, Cargill Animal Nutrition, Minneapolis, MN). Experimental diets were formulated to provide similar concentrations of protein (16.5% of DM), energy (1.63 Mcal of net energy for lactation/kg of DM), and neutral detergent fiber (41.7% of DM) and were fed once daily as a total mixed ration behind Calan doors for ad libitum intake. The cellulase enzyme provided 1,200 cellulase units of activity/g of product and was applied to the total mixed ration and allowed to mix for 5min before feeding. Before beginning the trial, all cows were trained to use Calan (American Calan, Northwood, NH) doors and then fed the alfalfa hay-based diet for 2 wk. Data collected during wk 2 were used as a covariate in the statistical analysis. At the beginning of the 6-wk experimental period, cows were assigned randomly to 1 of the 4 experimental diets. No interactions were observed between forage and enzyme for any measures. Daily DM intake; milk yield; concentrations of milk fat, true protein, lactose, and solids not fat; energy-corrected milk yield; and dairy efficiency were not different among alfalfa or Tifton 85 bermudagrass rations with or without cellulase enzyme supplementation. The results of this trial indicate that Tifton 85 bermudagrass haylage can replace alfalfa hay in diets fed to high-producing, lactating dairy cows without depressing DM intake or milk yield when rations are balanced for NDF. Although supplemental cellulase enzymes have been shown to improve ration digestibility and animal performance in previous trials, no advantages were observed in the current trial.


Assuntos
Bovinos/fisiologia , Celulase/administração & dosagem , Cynodon/metabolismo , Dieta/veterinária , Lactação/fisiologia , Medicago sativa/metabolismo , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos/metabolismo , Suplementos Nutricionais , Digestão/fisiologia , Ingestão de Alimentos , Feminino , Leite/química , Leite/metabolismo
15.
Sci Rep ; 10(1): 15821, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978433

RESUMO

Notoscopelus resplendens is an abundant myctophid in the region of the Central-Eastern Atlantic. As with a majority of other myctophid species, this species performs vertical migration, playing a key role in the oceanic food web and in carbon sequestration. We examined the reproductive biology of N. resplendens based on 579 specimens caught between 1997 and 2002 off the Canary Islands. We found that the maximum standard length (SL) was lower than the size reported by other authors. The sex ratio was not different from 1:1. The average size at first maturity (L50) was higher in females (60.34 mm SL) than in males (56.61 mm SL). The gonadosomatic index (GSI) at 50% sexual maturity in females was higher than that in males. The reproductive activity was observed from January to April, while from May onwards, the majority of fish caught were in the process of maturation. The macroscopic scale of maturation was validated through the histological analysis of the ovarian development. The batch fecundity was related to the standard length, with an average of 1068.69 ± 369.84 eggs/spawn. These first data obtained for N. resplendens indicated that it is a batch spawner with asynchronous ovarian development.


Assuntos
Peixes/fisiologia , Reprodução , Estações do Ano , Comportamento Sexual Animal/fisiologia , Maturidade Sexual/fisiologia , Animais , Ecossistema , Razão de Masculinidade , Espanha
16.
J Spec Oper Med ; : 110-120, 2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36800526
17.
Accid Anal Prev ; 117: 239-249, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29723735

RESUMO

This paper investigates the effect that texting with WhatsApp, one of the most common applications for instant messaging, exerts on driving performance. Because distracted driving also affects older drivers, who can have seriously compromised vision, we also analysed the associations between visual-function parameters and driving performance. A total of 75 drivers, experienced in sending WhatsApp messages (≥10WhatsApp messages/week), participated in this study and were divided into four age categories. Visual-function tests included contrast sensitivity with and without glare, retinal straylight and objective assessment of optical quality. Simulated driving performance was assessed under a baseline driving condition (without distraction) as well as a texting condition (WhatsApp messages) while driving. The participants used their own mobile phone. Lastly, objective results of driving performance were compared with subjective self-report data from the Driver Behaviour Questionnaire (DBQ). The analysis indicated that functional changes occurring with age, such as a lower contrast sensitivity and greater retinal straylight, were correlated with a higher number of collisions, longer distances driven outside the lane, and greater standard deviation of lateral position (SDLP). The results showed a significant main effect of age for the driving-performance parameters. Also, compared to the baseline, texting WhatsApp messages while driving worsens driving performance for all age groups, most notably among older participants. Thus, the older drivers' SDLP was ∼14% higher than that for the baseline average of all the other drivers and rose to 29% under distraction, reflecting the impact of secondary tasks. The negative effect of the use of the smartphone during driving was also reflected in the number of collisions, with a greater risk of accidents in all the groups of drivers (by 8.3% for young adults, 25.0% for adults, 80.5% for middle-aged adults, and 134.5% for older drivers). Lastly, participants' subjective responses indicated that younger drivers (18-24 years) had a higher risk of deliberately violating safe driving practices (p < 0.05). The present study demonstrates that texting WhatsApp messages while driving significantly impairs the ability to drive safely, with older drivers being the group most adversely affected. It would be recommendable to include other nonstandard vision tests, which have shown associations with driving performance, in the examination for driver licensing. This would help raise the awareness of older drivers concerning their visual limitations, permitting them to adopt compensatory measures to improve their driving safety. Nevertheless, it is also necessary to raise awareness among the younger drivers of the risks involved in behaviour behind the wheel.


Assuntos
Acidentes de Trânsito , Telefone Celular , Direção Distraída , Aplicativos Móveis , Assunção de Riscos , Smartphone , Envio de Mensagens de Texto , Adolescente , Adulto , Fatores Etários , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Desempenho Psicomotor , Risco , Segurança , Autorrelato , Transtornos da Visão , Adulto Jovem
18.
Clin Transl Oncol ; 9(4): 244-50, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17462977

RESUMO

INTRODUCTION: Standard fractionation radiation therapy (RT) combined with concomitant chemotherapy (CT) based on cisplatin schemes is actually the standard treatment for locally advanced non-resectable squamous cell carcinoma of head and neck (SCCHN). The appearance of taxoids has introduced a new kind of treatment with high antitumoral power. The aim of this study is to add more information about the role of this new approach. MATERIALS AND METHODS: Twenty-six patients with locally advanced non-resectable SCCHN were recruited at six institutions in Spain, between January 2001 and January 2003. Docetaxel was administered weekly, for 6 weeks, concurrently with RT. RESULTS: The mean total delivered dose of RT was 70'2 Gy (range 64-74 Gy). The median and mean duration of time were 63 days and 61 days (range 49-103 days) respectively. After a median time control of 19 months (range 3.3-42.2 months), the response rate was 83.4%. The median time to local progression was 16.4 months (95% confidence interval [CI]=4.4-28.4 months). The median survival time was 26.9 months, with one- and two-year overall survival of 66.9% (95% CI=48.1-85.7%) and 57.5% (95% CI=37.3-77.7%) respectively. The median duration time response was 15.1 months (95% CI=3.7-26.5 months). The median time until treatment failure was 9.4 months (95% CI=4.7-14.1). Incidence of grade III-IV mucositis was 88%, neutropenia 72% and skin toxicity 92% (24% grade III-IV). The incidence of severe late toxicity (grade III and IV) due to RT/CT was 31.4%. CONCLUSIONS: Although therapeutics results are equivalent to cisplatin schemes of concurrent CT-RT, mucositis and cutaneous toxicity registered in this trial must be considered as limiting factors to application of this new approach.


Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , Taxoides/uso terapêutico , Adulto , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Terapia Combinada , Intervalos de Confiança , Docetaxel , Feminino , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Estimativa de Kaplan-Meier , Avaliação de Estado de Karnofsky , Neoplasias Laríngeas/tratamento farmacológico , Neoplasias Laríngeas/mortalidade , Neoplasias Laríngeas/patologia , Neoplasias Laríngeas/radioterapia , Laringe/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Primárias Múltiplas/tratamento farmacológico , Neoplasias Primárias Múltiplas/mortalidade , Neoplasias Primárias Múltiplas/radioterapia , Neoplasias Faríngeas/tratamento farmacológico , Neoplasias Faríngeas/mortalidade , Neoplasias Faríngeas/patologia , Neoplasias Faríngeas/radioterapia , Faringe/patologia , Radioterapia/efeitos adversos , Dosagem Radioterapêutica , Taxoides/administração & dosagem , Taxoides/efeitos adversos , Fatores de Tempo , Resultado do Tratamento
19.
J Spec Oper Med ; 17(4): 133-137, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29256213

RESUMO

BACKGROUND: The latest terrorist attacks in Europe and in the rest of the world, and the military experience in the most recent conflicts leave us with several lessons learned. The most important is that the fate of the wounded rests in the hands of the one who applies the first dressing, because the victims usually die within the first 10 minutes, before professional care providers or police personnel arrive at the scene. A second lesson is that the primary cause of preventable death in these types of incidents involving explosives and firearms is massive hemorraghe. OBJECTIVE: There is a need to develop a training oriented to citizens so they can identify and use available resources to avoid preventable deaths that occur in this kind of incidents, especially massive hemorrhage. METHODS: A 7-hour training intervention program was developed and conducted between January and May 2017. Data were collected from participants' answers on a multiple-choice test before and after undertaking the training. Improved mean score for at least 75% of a group's members on the posttraining test was considered reflective of adequate knowledge. RESULTS: A total of 173 participants (n = 74 men [42.8%]; n = 99 women [57.2%]) attended the training. They were classified into three groups: a group of citizens/ first responders with no prior health training, a group of health professionals, and a group of nursing students. Significant differences (ρ < .05) between mean pre- and post-training test scores occurred in each of the three groups. CONCLUSION: There was a clear improvement in the knowledge of the students after the training when pre- and post-training test scores were compared within the three groups. The greatest improvement was seen in the citizens/first responders group.


Assuntos
Educação não Profissionalizante , Primeiros Socorros , Hemorragia/terapia , Terrorismo , Ferimentos e Lesões/terapia , Bandagens , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde , Técnicas Hemostáticas , Humanos , Masculino , Avaliação de Programas e Projetos de Saúde , Espanha , Estudantes de Enfermagem , Torniquetes
20.
Arq. bras. med. vet. zootec. (Online) ; 72(5): 1813-1820, Sept.-Oct. 2020. tab, graf, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1131539

RESUMO

The use of anesthetics in fish farming is essential to reduce stress during management. The present study proposes to evaluate the effect of eugenol as an anesthetic for the management of curimatã (Prochilodus nigricans). Fifty specimens were used (221.34±9.0 g; 25.8 ±1.1 cm), submitted to five treatments with concentrations of 0, 25, 50, 100 and 200 mgL−1 eugenol for 10 min. The times required to reach each anesthetic stage and the recovery of each fish were recorded. To check bloodglucose levels individual blood samples were taken from the fish before immersion and after ten minutes of anesthetic exposure. Evaluation of the anesthetic effect ongills was performed by histopathological analysis. The concentration of 50 mgL−1 was within the ideal limit of three minutes recommended for surgical anesthesia induction and did not significantly increase glucose levels when compared to the control group (35.7±19.4 mg dL−1), besides not causing gill injuries. At this concentration the fish presented controlled blood glucose levels within the basal levels, besides not taking the risk to have later problems concernig mortality, because this concentration ensures the good health of the gills and good recovery of the animals.(AU)


O uso de anestésicos em pisciculturas é indispensável para reduzir o estresse durante o manejo. O presente trabalho propôs avaliar o efeito do eugenol como anestésico para manejo do curimatã (Prochilodus nigricans). Foram utilizados 50 espécimes (221,34±9,0 g; 25,8 ±1,1 cm), submetidos a cinco tratamentos com concentrações de 0, 25, 50, 100 e 200 mg L−1 de eugenol em exposição de 10 minutos. Foram registrados os tempos necessários para atingir cada estágio anestésico e a recuperação de cada peixe. Para verificação dos níveis de glicose sanguínea, foram realizadas coletas individuais de sangue dos peixes antes da imersão e após os 10 minutos de exposição ao anestésico. A avaliação do efeito do anestésico sobre as brânquias foi realizada por meio de análises histopatológicas. A concentração de 50 mg L−1 ficou dentro do limite ideal de três minutos preconizado para indução à anestesia cirúrgica e não elevou significativamente os níveis de glicose quando comparada ao grupo controle (35,7±19,4 mg dL−1), além de não provocar lesões branquiais. Nessa concentração, os peixes apresentaram níveis de glicose sanguínea controlada, dentro dos teores basais, além de não correrem o risco de apresentarem problemas posteriores em relação à mortalidade, pois essa concentração garante a boa saúde das brânquias e uma boa recuperação dos animais.(AU)


Assuntos
Animais , Eugenol/administração & dosagem , Caraciformes , Período de Recuperação da Anestesia , Aquicultura/métodos , Anestésicos Gerais
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